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By Eckley B. Coxe

The subject of this paper will be treated as briefly as possible under the following heads : I. The latest designs of some of the machinery used at these collieries in the preparation of coal. 11. The means employed for elevating, conveying and transporting the coal and slate in and about the breaker. 111. The means employed for raising the coal from the mines to the top of the breaker. IV. The iron breaker as a structure. V. The preparation of the coal as effected in the iron breaker. A key to the plates and the letters and numbers designating different parts, will be found at the end of the paper. I. Preparing Coal. Anthracite coal as it comes from the mines is not marketable. The "run of mine" cannot, as in the case of bituminous coal, be sold. Anthracite, being very compact and practically free from volatile combustible matter, burns only at the surface, and it is, therefore, deemed important to have the lumps as nearly of a uniform size as possible, so that between them a large amount of surface will remain exposed to the action of the air without checking the draught too much, or allowing enough air to pass to cool the coal below the ignition-point, In other words, if the pieces of coal of the size of a chestnut and smaller are mixed with lumps of the size of an egg they fill the air-passages and prevent a free draught. It has long been recognized, therefore, that one of the most important points in preparation is to have a uniform sizing, and also to make as large a number of different sizes as can be produced without too

Jan 1, 1891

By E. G. Williams

Manganese-ore has been found upon the Isthmus of Panama throughout' a region of nearly three hundred square miles, over the greater part of which, however, it is known only in small bodies without commercial value. Only six mines, controlled by two companies, have actually shipped ore, although a large area has been taken up in miningelaims. The ore-bearing region extends along the coast of the Carib. bean Sea, beginning on the west near Puerto Bello and extending easterly about 35 miles toward Point San Blas. Ore has been discovered in the interior, at a maximum distance of about 10 m. from the coast. Fig. 1 is a map of a portion of the Isthmus

Jan 1, 1903

By Ralph Arnold

LESS than eight months ago at the annual meeting of the American Institute of Mining and Metallurgical Engineers, attention was called to the demoralizing effect of the abnormal oil production of Mexico on the oil situation in the United States, and it was predicted that this unstabilizing influence would probably become impotent in 18 to 24 months through ' the exhaustion of the principal producing fields of Mexico, unless new fields were found in- the meantime. When this statement was made, the daily production of Mexico was about 600,000 bbl. of crude oil; now it is about 350,000 bbl. No new pools of consequence have been opened, although extensions have been made to two old pools. Over 200,000 bbl., or more than half of the present daily production, comes from Los Naranjos, Amatlan and North Zacamixtle fields, in which practically every well is so affected by salt water that the potential production dropped 50 per cent. in the month of September, clearly indicating that these fields are moving rapidly toward extinction. How much longer the one remaining important pool will last is a matter of conjecture.

Jan 1, 1921

By C. Richard Tinsley

Like most minerals, coal is inherently a demand-limited commodity. The very sedimentary nature of its occurrence implies greater availability potential than demand. But this situation is overridden by economics among fuels, between coals, and within coal blends. Such considerations make coal forecasting a very hazardous profession indeed. THERMAL COAL If one thought that the lead times involved with a mining project were very long, one has obviously not been exposed to the planning process in the electric generation business - a process seriously confounded by shifts in load growth, environmental pressures, capital intensity, security of fuel sourcing, inter-fuel economics, and so on. But as a general rule, the near-term forecasts for thermal coal can reliably be based on a bottom-up, plant-by-plant analysis. Cement plant conversions can also be reasonably estimated next in order of reliability, although they have a much wider spectrum of coal qualities and fuel sources to choose from with a notably higher tolerance for sulfur and ash. Finally, industrial demand can be assembled from the estimates for conversions by pulp/paper plants, chemical plants, etc. The industrial sector is harder to estimate, since it may involve small boilers or dual-fired units. Assessing demand in the Pacific Rim is relatively a straightforward process in the near term because the major importing countries are all located on the Asian continent with either negligible or very minor (yet stable) indigenous coal production, (itself often operated on a subsidized basis). Furthermore, all imports are seaborne. These major importers are Japan, Korea, Taiwan, and Hong Kong with Thailand, Singapore, and Malaysia up-and-coming consumers. The suppliers to this market all have substantial reserves to back up decades of exports to these countries. Australia, the US, Canada, South Africa, China, and the USSR dominate the supply side. The second oil-shock of 1979/1980 has convinced the importers that reliance on oil can be expensive and eminently interruptible. Thus, they are determined to diversify away from oil' to nuclear and coal for generating electricity and for coal for other purposes where possible. This trend is seen to continue even in the face of the oil glut worldwide and oil-price reductions in early 1982. But the importers are also convinced that reliance on one coal source and, in particular, one infrastructure route for the coal chain from mine to consumer can be equally expensive and interruptible. Strikes in the US and Australia; excessive demurrage at certain ports; relegation of coal to a lower priority on multiple-use railroads in the USSR and China; and concern over escalation on high-infrastructure or high-freight coal chains are among the risks worrying the importers. As a consequence, Pacific Rim thermal coal purchases are being allocated among supplier nations, between ports, and within each country. An example of Japan's shift away from Australia and toward the US and Canada is shown in the estimates in Table 1. But the confidence of the import estimates deteriorates sharply beyond the plant conversion timetables and construction schedules in the near term. If part of the second generation of coal-fired power plants can handle lower-energy coals, the field of suppliers could widen to accept sizeable tonnages from Alaska, Wyoming, Alberta, or New Zealand resources. These supply sources generally have some infrastructure or freight advantage to compensate for their lower quality and to compete on a delivered energy-unit basis. These also offer diversification in sourcing. And the possibility of coal liquefaction in Japan further widens the sourcing network. A great number of Pacific Rim coal forecasts have been generated, especially for Japanese thermal-coal imports which are expected to grow strongly in the 1980's. Since the Japanese themselves have not yet settled their energy policy, the exact numbers are hard to call. Nevertheless, at 50 million tonnes of imports in 1990, Japan would consume 50-60% of the total Asian thermal coal imports as shown on Tables 2 and 6. The next most important consumers are the "island" nations of Korea, Taiwan, and Hong Kong (see Tables 3-5). All three are embarking on power plant developments usually with captive unloading facilities, capable of accepting more than 100,000-dwt vessels. Korea, with no-indigenous bituminous coal, is not especially enamoured with US coals, which are deemed too heavily loaded by freight and infrastructure costs -- up to 70% of the delivered price. Thermal coal contracts are presently split to Australia (70%) and to Canada (30%). Korea Electric Power Co. is already considering second-generation boilers capable of burning lower-quality coals than the present standard. Korea does burn domestic anthracite.

Jan 1, 1982

By AIME

THE history of the Mine La Motte area covers a greater period of time than any other mining operation west of the Mississippi, for it was almost exactly four centuries ago that the white man first visited the region. In May 1541 a few men from the party of Fernando de Soto traversed the place looking for silver which they understood the Indians had found in the vicinity. Some historians say that De Soto himself visited the place sometime later. No other white man came through again until the early 1700's. In 1712 King Louis XIV of France granted to Antoine Crozat a charter for transacting all business and government in the vast domain of the New Continent stretching from the Gulf of Mexico northward indefinitely. This

Jan 1, 1947

By Jose J. Alvarez

INTRODUCTION Three major plant processes control the operation of an uranium in-situ mining plant. The three pro- cesses can be categorized under the headings termed - loading, elution, and precipitation. All other plant processes can be subcategorized under the three. In summary, the major plant processes in an in- situ mining plant are: 1. Loading - The pregnant lixiviant from the production wells flows through anion exchange resin. The loading of the uranium on the resin is controlled by various factors, such as ionic strength, valence, functional groups, etc. 2. Elution - The uranium-loaded resin is eluted or regenerated by a high ionic strength solution. The effluent from this process is de- fined as the pregnant eluate. 3 . Precipitation - The pregnant eluate is chemically treated to attain the ideal conditions for the selective precipitation of uranium. Hydrogen peroxide is an ideal precipitating agent under URI conditions. This paper will focus on two of the major processes: Elution and Precipitation. For the most part this relatively young industry has grasped the theory of liquids in continuous flow for the operation of the plant processes. Likewise, URI initially operated the two processes of interest with the continuous flow concept. Through laboratory experiments, URI has abandoned the flow concept and operates the eluting and precipitating stages with the concept of "batch" processes, whereby only one container, filled to a specified liquid level, is chemically processed. In the proceeding sections, each of the two pro- cesses will be discussed in detail, from their original concept to the present operation. Only minor modifications were made to the existing circuits for the conversion with results revealing a greater level of efficiency. ELUTION The elution of the loaded anion exchange resin can be achieved by different high ionic strength solutions. The selection of constituents is dependent on both chemical and economic considerations (i .e., efficiency and operating/restoration factors). The regenerant presently used is a pH 9.5 solution containing 7.5% NaCl and a mixture of Na2C03/NaHC03. expressed as 2.5% NaHC03.

Jan 1, 1980

By William G. Kranz

Discussion of the paper of WILLIAM G. KRANZ, presented at the San Francisco meeting, September, 1915, and printed in Bulletin. No. 101, May, 1915, pp. 927 to 930. M. PETINOT, Niagara Falls, N. Y. (communication to the Secretary*). -I have read this paper with considerable interest and agree perfectly with Mr. Kranz that steel for castings made in an electric furnace is not necessarily, because of that fact, all good steel, and also that the qualities which he mentions, such as absence of segregation, elimination of `sulphur, great tenacity, etc., can be obtained in an electric furnace if operated under proper metallurgical conditions. An unusually low content of sulphur in steel for castings is not, of course, an absolute necessity and the range of this element usually obtained in steel made in basic open-hearth furnaces is sufficiently low to meet all physical requirements. The main factor in making steel for castings, regardless of the process, is the complete deoxidation of the bath to prevent the formation of

Jan 12, 1915

By W. M. Corse

AT THE TURN of the century the nonferrous alloy industry was awakening to the value of scientific metallurgy, and brass foundries and rolling mills began to establish their own research laboratories for scientific research and control. As the industry grew and its scope broadened it became apparent that an organization was needed that would stand in the same relation to the nonferrous industry as the American Foundrymen's Association did to the iron foundry business. The brass founders' group of the foundrymen's association discussed the matter and it was finally decided to appoint a com- mittee to draw up a constitution for a new organization to be known as the American Brass Founders' Association. Charles J. Caley was chairman and Dr. Richard Moldenke secretary of this committee. The object of the organization as defined by the constitution was the study of the technological development of alloying and founding non- ferrous metals, and furthering the advance of nonferrous metallurgy and the standardization of materials and operations in cooperation with the Bureau of Standards and engineering societies.

Jan 1, 1932

By C. S. Simons, G. Major-Marothy, M. A. K. Grice, D. A. Dahlstrom

The vacuum filter operating variables that influence cake moisture are discussed. The influence of temperature control, particularly through application of steam to the cake, is emphasized. Results of pilot plant studies on filtration of fine hematite concentrates are presented and discussed, and are shown to support the theoretically-derived conclusions. Results on fine magnetite concentrates are also used to support the argument. The relative merits of disc and drum filters from the standpoint of cake moisture are discussed. Moisture content has always been recognized as one of the most important properties of concentrates used as pellet plant feed. Most iron ore concentrates are produced by wet methods, and are finally de-watered on filters. Obviously, a real economic advantage accrues to the ability of control the moisture content of the filter cake within the range required for optimum pellet production. Another consideration, also, has been receiving increasing attention recently. Transoceanic shippers of concentrate cargoes are critically assessing the hazards of excess moisture. The nature and magnitude of these risks have been described, ' and it appears that their elimination may require that residual moisture be somewhat lower than the limit for proper pelletization. Coarse, very free-filtering materials, such as the products of spirals, are usually best handled on top-feed types of machines. The moisture content of the cake may be held at a specified value by proper design and operation, taking into account cake thickness, air-flow rate, and drainage time. Fine-grained concentrates, with which we will be concerned here, must be filtered on Drum or Agidisc machines. With many of these materials, it is possible, by proper design, to meet cake moisture requirements with a conventional filter station. The first installations to produce high-grade pellets from magnetic taconites fell in this class. In fact, the design criteria were developed in connection with operations of Reserve Mining Co. at Silver Bay, inn.,2 and these have been verified repeatedly in other mills. The trend today, however, is toward the production of more difficultly dewatered concentrates. This is due on the one hand to the increasing attention being given to non-magnetic ores, which tend to be far slimier, and therefore much more retentive of moisture, than the magnetites. On the other hand, the pressure to improve the grade of the magnetic ores is leading to finer grinds, which also are more difficult to dewater. In the latter case, the decision to improve grade in an existing operation by finer grinding for better liberation may lead to two unattractive alternatives: 1) substantially higher bentonite consumption, plus the risk of poorer quality pellets, from high cake moisture, or 2) installation of a thermal dryer. There is, however, a third alternative. In recent papers by two of the authors3,4 it was shown that for many materials a significant decrease in cake moisture can be obtained by applying live steam to the cake face during the drying part of the filter cycle. Further, this limited drying appears to have distinct economic advantages compared to thermal drying. It is the purpose of this paper to explore the third alternative. To do this, the results of an extensive pilot study of steam filtration of a hematite flotation concentrate will be critically examined. This study was sufficiently broad so that a number of alternate suggestions (besides steaming the cake) for reducing moisture content were tested, and comparative data for both Drum and Disc filters were obtained. The work was particularly interesting since the concentrate has a high Blaine surface, and is therefore particularly difficult to dewater to the levels required. FILTER CAKE MOISTURE The significant difference between concentrate filter cake as discharged from the filter, a cargo of that same filter cake during or after shipment, and a green ball formed from that filter cake is in the relative volume of voids, or porosity. In every case, the material is a collection of small solid particles held together by the cohesive forces of a liquid. The physical properties of the aggregate are determined by the

Jan 1, 1967

By W. A. Vine

When a hole is made in a stressed solid, such as rock pierced by mine openings, equilibrium of the solid is destroyed. To restablish that equilibrium the stress condition in the rock surrounding the opening becomes rearranged. This rearrangement may or may not develop local stresses in the vicinity of the opening which exceed the elastic strength of the rock. Since stability of the opening depends, therefore, on the strength of the naturally occurring rock surrounding the opening, this rock is an engineering material of construction, and all rock affected by the associated opening or system of openings may be considered a structure. The term invert is chosen to describe the formation of the structure built from the inside, as it were, and a consequence of mining rather than an entity built for a purpose. By definition, an invert structure is formed when openings are made underground and is com- posed of that material on the solid side of a rock-air interface wherein the stress condition is affected by the associated opening or system of openings. The shape of an invert structure is never clearly defined; the skin of the structure may be mapped, and even described, but the boundary of the structure within the solid rock mass must be arbitrarily set.

Nov 1, 1955

By M. Kashiwada

The zinc leach residues are introduced into waelz kiln to fume volatile metals and before the end of 1967, the waelz-fume containing zinc, lead, cadmium and indium was directly recycled back to the leaching process for the production of electrolytic slab zinc. However, since 1968, we have been recovering with success those valuable metals contained in the fume separately instead of direct leaching. According to the improved process, the waelz-fume, after being mixed with chloridizing agents, is fed into the rotary kiln to be roasted, wherein most of lead and cadmium content is collected as fume and most of zinc remains in the calcine. Zinc calcine thus obtained, containing 70 to 75 per cent zinc and, less than 1.0 per cent lead is sent to zinc plant for further recovery and the fume containing 40 to 50 per cent lead and 3 to 6 per cent cadmium is further processed to recover lead, cadmium and indium. The advantage of this process can be secured to the utmost when it is combined with the following subsequent treatments. (a) Blast furnace smelting of non-magnetic waelz slag to recover copper, silver and gold as matte. (b) Gallium recovering process from magnetic waelz slag. (c) Soda process of lead bearing cake produced after removing cadmium and indium from the said fume. Thus the extractions of zinc, lead and cadmium from leach residues account for 87 per cent, 72 per cent and 85 per cent respectively.

Jan 1, 1970

By C. W. Covington, H. C. Cook, J. F. Libsch

Sputtered aluminum thin films were prepared in each of two conventional bell-jar vacuum systems. One system utilized an inner "getter sputtering" enclosure; the second system was a standard diode sputterirlg arrangement. Consistent and repeatable film properties were obtained in both systems provided sufficient cleanup and presputter time was allowed. The various problems associated with aluminum sputtering are discussed, with pavticular attention to the vzinimization of film contamination by outgassing and oxidation. The growth and structure of the aluminum thin films were studied with the aid of electron wzicroscopy and related to deposition rate, substrate temperature, and film thickness. The resistivity of the films was correlated to film structure and surface roughness. Resistiuities as low as 3.5 microhm-cm (2.3 x bulk resistiuity) were measured for relatively thick films (20,000). THIS investigation was undertaken to explore the problems and film characteristics associated with the sputtering of aluminum. Earlier work reported on aluminum sputtering has stressed the contamination of both the cathode and film as well as abnormally low deposition rates.' Data on sputtering yields,3 however, indicate that aluminum sputtering could be practical. Recently, it was shown by Theuerer and Hauser3 that aluminum sputtering was feasible in a conventional oil-diffusion pumped vacuum system provided an inner "getter sputtering" enclosure was employed to minimize gaseous contamination. This technique employs the getter action of aluminum to produce extremely low reactive gas partial pressures in the deposition zone. Aluminum films have already found use in solid-state electronic devices such as transistors and integrated microcircuits. To the present time, most aluminum films have been prepared by evaporation due to the ease with which this metal can be evaporated. Controlled sputtering of aluminum offers a number of advantages over evaporation, however, such as 1) manufacturing compatibility with other metals which must be sputtered, 2) better control of process variables resulting in more repeatable and uniform films, 3) generally better adhesion resulting from higher-energy metal atoms, 4) built-in material supply for continuous operation, and 5) the ability to deposit alloys. The data presented in this paper are the result of two separate studies. One study utilized a small "getter sputtering" enclosure (System A) and was concerned with the structure and properties of thin aluminum films up to about 1600A thick. In this thickness range, study of the film structure was possible with transmission electron microscopy. The second study was conducted with a conventional diode sputtering apparatus (System B) and covered $ much wider range of film thickness up to about 34,000A. Emphasis was placed on developing techniques which would extend aluminum sputtering to an existing in-line continuous deposition process.4 I) EQUIPMENT AND PROCEDURE System A. Fig. 1 shows a schematic of the "getter sputtering" inner chamber used and Fig. 2 is a photograph of this chamber mounted on an 18-in. access ring of a standard liquid-nitrogen trapped bell-jar vacuum system. This chamber was designed after a similar system used by Theuerer and auser.3 The configuration allowed the glow to emanate in all directions from the cathode. Argon (99.99') was allowed to enter only at the top of the chamber such that most of the reactive gases entering with the argon were reacted with the aluminum vapor and deposited on the chilled walls of the chamber before reaching the deposition zone. Provision was also made as shown, Fig. 1, for heating and cooling the substrate from about 20" to 400°C. Two substrate materials were used: Corning 7059 glass (12 by 12 by 0.048 in.) and carbon films about

Jan 1, 1967

By Alfred E. Hunt

The charge to be described was made in a seven-ton furnace, with a hearth twelve feet long and eight feet wide, with three gas and three air ports on each side. The stock of the entire heat was charged cold in one hour and five minutes, a part of the pig being first placed upon the bottom to protect it, then upon it the plate-scrap and blooms, and finally the remainder of the pig—some two thousand pounds. In fire hours and twenty-five minutes after beginning the charge the metal was melted down level, and two hundred pounds of hot twelve-per cent. spiegel was charged, care being taken to have it entirely immersed in the bath. In two hours more the bath was thoroughly melted and hot, and began to boil, i. e., the carbon began to be oxidized and evolved through the bath of covering slag as carbonic acid and carbonic oxide gases. Seventy-five pounds of lumps of Republic specular iron ore were added at this time, increasing the action, so that in ten minutes after the metal was in active ebullition. A test of the metal showed it to have about 0.90 per cent. carbon. One hour after the first ore was added a test was again taken, after thorough rabbling of the metal, and it was found to be 0.37 per cent. carbon. One hundred pounds more of lump Republic ore and about seventy-five pounds of limestone were then added, and fifty minutes later, after the bath was thoroughly rabbled, a -test showed the metal to have 0.23 per cent. carbon. Twenty-five pounds more of Republic iron ore were added and the metal allowed to boil for twenty minutes, when a test, after rabbling, showed the carbon to be 0.18 per cent. and the manganese to be 0.01 per cent.; the slag fracture was vitreous and of a very dark-green color. About forty pounds of limestone were added, and, the metal being hot and in a state of quiet ebullition, a hickory pole of twelve feet length and about four inches diameter, was run through the aperture in the centre door and held in a steady inclined position in the bath, with the end touching the bottom, the pole being shoved in further as it was burned away. The bath was carefully watched to see that the action that ensued was not too violent, the pole being several times

Jan 1, 1884

By M. Kaufman, A. E. Palty

The phase structure and aging characteristics of two nickel-base alloys, Inconel 718 and 702, were investigated. Wrought and cast Inconel 718 showed ArisCb as the major hardening phase, as well as ture was positively identified. Inconel 702 had Ni3Al as the major hardening phase, as well as Cr7C3-of the phase amounts with temperature was determined. 1 HE value of phase structure and aging rate information in the utilization of alloys has been well established. As part of a continuing program, the results obtained on two nickel-base alloys, hconel 718 and Inconel 702, are presented here. Inconel 718 is a relatively new alloy considered for application in both sheet and cast form. Its novelty lies in the use of high columbium tantalum levels in a Ni-Cr-Fe base. No previous work on this type of alloy has been reported in the literature. Inconel 702 is being used now as an oxidation-resistant sheet alloy. Occasional fabrication problems spurred work on its basic structural behavior. The composition of 702 is essentially nichrome plus aluminum and titanium for strengthening and added oxidation resistance. This puts it in the basic class of other nickel-base alloys which have already been studied. The two alloys will be treated separately. INCONEL 718 Phase Study Methods. The phases present after the various conditions investigated were determined by X-ray diffraction analysis of two different elec-trolytically extracted residues and microscopic examination. The extraction methods, using 10 pct HC1 in alcohol and 10 pct H3PO, in water and the X-ray technique have been described previously.' The effect of temperature on the phase behavior was studied on sheet material using the following heat treatments: 2250°F, 2 hr, ice brine quench 1300 100 hr, water quench 2250°F, 2 hr, ice brine quench 1400°, 100 hr, water quench 2250°F, 2 hr, ice brine quench 1500°F, 100 hr, water quench 2250o 2 hr, ice brine quench 1700°F, 48 hr, water quench 2250°F, 2 hr, ice brine quench 1850°, 24 hr, water quench 2250°, 2 hr, ice brine quench 2000°F, 6 hr, water quench The high solution temperature was an attempt to dissolve as many phases as possible without causing melting. Aging exposures were made longer than normal heat treating times in order to approach equilibrium conditions more closely. Cast material was examined only in the as-cast condition and with the normal heat treatment (1700°F, 1 hr, air cool 1325oF, 16 hr,air cool). Materials. The full phase study was performed on sheet specimens approximately 1/2 in. by 2 in. by 1/16 in. The cast pieces were cut from the gating system of a vacuum-cast test piece. An all weld-metal specimen was made by running many weld beads on the sheet using filler made from the sheared edges of the sheet. All external contamination was removed by belt-sanding followed by an electro-polishing treatment. The typical composition of wrought Inco 718 is as follows: The alloy is air-melted. Cast hco 718 may have higher molybdenum. Due to the expectation of finding a Ni-Cb phase (Ni, Cb) for which no X-ray diffraction pattern was available in the ASTM Index, a special 5 Ib heat to the stoichiometric composition of this intermetallic

Jan 1, 1962

By P. W. Barton, A. A. Johnson, E. J. Hughes

THE only systematic work on the effect of carbon on the recovery and recrystallization kinetics of iron so far reported in the literature is that of Venturello et al.1 These workers found that doping high-purity iron so that it contained up to 86 ppm C caused a marked retardation of recovery but had little or no effect on the recrystallization kinetics. Such evidence for an effect as was obtained was inconclusive. In the course of a study of electron-beam zone-refined iron the authors have recently examined the effect of added carbon on the recrystallization kinetics of this material. The amount of carbon added was about 50 pct more than was used by Venturello et 01. and definite evidence was obtained that carbon at this level retards recrystallization. The starting material was taken from a batch of 0.2-in.-diameter Johnson-Matthey spectroscopically pure iron rods which had been further purified by being given three passes at 4 in. hr-1 in a standard MRC electron-beam zone-refining unit. The purity of this material. which was used in two other investigations of the properties of high-purity iron,2,3 was established by an extensive series of analyses. Four laboratories, the National Research Corp., Newton, Mass., the Naval Research Laboratory, Washington, D.C.. the Battelle Memorial Institute, Columbus, Ohio, and the National Physical Laboratory. Teddington. Middlesex, England. carried out analyses for carbon. oxygen. and nitrogen. and in addition a complete mass-spectrograph analysis was carried out at Battelle. In all, twelve analyses were carried out for carbon, seventeen for oxygen and twelve for nitrogen. The amounts of these elements found to be present were 10 * 7, 8 i 5, and 0.9 i 0.1 ppm, respectively. The limits given are rms deviations. Two results, one of 46 ppm of oxygen and another of 31 ppm of nitrogen, were rejected as anomalous. The mass-spectrograph analysis revealed the major impurity to be 25 ppm of tungsten. All of the other elements detected were present in amounts less than 0.5 ppm. Some of the rods were doped with carbon by being immersed in a suspension of carbon in oil, heated in a vacuum at 400°C, and then zone-leveled to make the distribution of carbon uniform. Carbon analyses carried out on three of the doped rods gave a mean value of 130 ± 45 ppm. Some of the doped and undoped rods were deformed 58 pct by swaging and cut into specimens 1/2 in. in length. Isothermal recrystallization experiments were then carried out on them at 575", 600°, 615", 630°, and 650°C, the volume fraction of each specimen recrystallized being measured by a point-counting method described by Hilliard and Cahn.4 The results for the two types of specimens are shown separately in Figs. 1 and 2. In Fig. 3 the pairs of recrystallization curves for each temper-

Jan 1, 1965

By C. K. Leith, W. J. Mead

In 1911, we published in the Transactions a brief account of the lateritic alterations of serpentine in eastern Cuba, producing the important iron-ore deposits of the Mayari and Moa districts.' The special feature of that article was a quantitative treatment of the alterations, based on analyses, to show just what had happened in terms of chemical, mineralogical, and physical changes. Professor Kemp has published an interesting account of these ores, containing additional quantitative observations of his own, tending essentially to confirm the nature of the changes that had been worked out.2 His discussion suggests to us the desirability of publishing certain additional quantitative data which were not included in our previous article. This seems especially desirable because quantitative measurements of lateritic alterations are rare, and this particular case may be regarded as typical of a fairly wide range of alterations of this kind. At the time of our examination of Mayari and Moa deposits 29 complete analyses were supplied us by the chemists of the Spanish-American Iron, Co., representing a graded series from the unaltered serpentine rock below to the ore at the surface. These analyses are given in the accompanying table. The mineralogical composition of the ores and rocks is comparatively simple and can be easily calculated from the analyses. In Fig. 1 the mineralogical changes from the serpentine rock below to the lateritic iron ore above, based on the analyses, are expressed in terms of weight, assuming alumina to have remained constant during the alteration. It is not easy by mere inspection of this table of analyses to determine what the progressive chemical changes have been in development of the ore. In order to bring this out clearly, the analyses have been graphically represented in Fig. 2 in such a fashion as to show the progressive additions and losses of substances during alteration.

Jan 1, 1916

By J. C. F. Randolph

This mill being now in successful work, it seems proper to record some professional memoranda concerning it. It is intended to handle an unusual ore, in a locality difficult of access, and its arrangement and method of procedure present some novel features of interest. It was prepared for the San Miguel property at Batopilas, State of Chihuahua, Mexico, owned by the Consolidated Batopilas Silver Mining Company of New York, at present under the management of ex-Governor Alexander R. Shepherd. This property contains a large series of more or less parallel veins, worked through a deep cross-cut tunnel 1300 feet in length. The vein rock of these veins is calcapar in diorite. While, near the stirface, ruby silver, black

Jan 1, 1882

By Charles W. Bloomquist

The profitability of miscible flooding in a hypothetical target oilfield is examined. The major costs, including Windfall Prof it Tax, are identified and their re1ative importance are discussed. The sensitivity of profit to important physical and economic variables is evaluated and discussed, including variance in oil recovery, oil price, injectant requirements, injectant cost, and capital requirements. Economic sensitivities to important development and operating decisions such as timing, Spacing, Slug size, and gas recycling are also analyzed. The Windfall Profit Tax (WPT) as it applies to gas miscible EOR projects is reviewed. The effect of WPT on each of the various project cases is analyzed and the effect of reduced WPT on remaining production from existing operations is evaluated. Tax implications are compared for integrated vs. "independent" controlled projects and the alternative of expensing vs. capitalizing tertiary injectants is also evaluated. The impact of the Net Income Limitation in reducing WPT. during early and late project life is determined and discussed.

Jan 1, 1982

By J. Chipman, M. N. Dastur

The importance of dissolved oxygen as a principal reagent in the refining of liquid steel and the necessity for its removal in the finishing of many grades have stimulated numerous studies of its chemical behavior in the steel bath. From the thermodynaniic viewpoint the essential data are those which determine the free energy of oxygen in solution as a function of temperature and composition of the molten metal. A number of experimental studies have been reported in recent years from which the free energy of oxygen in iron-oxygen melts can be obtained with a fair degree of accuracy for temperatures not too far from the melting point. Certain discrepancies remain, however, which imply considerable uncertainty at higher temperatures; also several sources of error were recognized in the earlier studies. It has been the object of the experimental work reported in this paper to reexamine these sources of uncertainty and to redetermine the equilibrium condition in the reaction of hydrogen with oxygen dissolved in liquid iron. The reaction and its equilibrium constant are: H2 (g) + Q = H2O (g); K1 _ PH2O / [1] Ph2 X % O Here the underlined symbol Q designates oxygen dissolved in liquid iron. The activity of this dissolved oxygen is known to be directly proportional to its concentrationl,2 and is taken as equal to its weight percent. The closely related reaction of dissolved oxygen with carbon monoxide has also been investigated:3,4,5 co (g) +O = CO?(g); K _ Pco2___ [2] K2= pco X % O [2] The two reactions are related through the wat,er-gas equilibriuni: H2 (g) + CO2 (g) = CO (g) + H2O (g); K2 = PCO X PH2O [3] PH2 X PCO2 and with the aid of the accurately known equilibrium constant of this reaction, it has been shown5 that the experimental data on reactions [1] and 121 are in fairly good, though not exact, agreement. Experimental Method Great care was taken to avoid the principal sources of error of previous studies, namely, gaseous thermal diffusion and temperature measurement. The apparatus was designed to provide controlled preheating of the inlet gases and to permit the addition of an inert gas (argon) in controlled amounts, two measures found to be essential for elimination of thermal diffusion. A known mixture of water vapor and hydrogen was obtained by saturating purified hydrogen with water vapor at controlled temperature. This mixture, with the addition of purified argon, was passed over the surface of a small melt (approximately 70 g) of electrolytic iron in a closed induction furnace. After sufficient time at constant temperature for attainment of equilibrium the melt was cooled and analyzed for oxygen. GAS SYSTEM A schematic diagram of the apparatus is shown in Fig 1. Commercial hydrogen is led through the safety trap T and the flowmeter F. The catalytic chamber C, held at 450°C, was used to convert any oxygen into water-vapor. A by-pass B with stopcocks was provided so that the hydrogen could be introduced directly from the tank to the furnace when desired. From the catalytic chamber the gas passed through a water bath W, kept at the desired temperature by an auxiliary heating unit, so that the gas was burdened with approximately the proper amount of water vapor before it was introdvced into the saturator S. All connections beyond the catalytic chamber were of all-glass construction. Those connections beyond the water bath were heated to above 80°C to prevent the condensation of water vapor. After the saturator, purified argon was led into the steam-hydrogen line at J, and finally the ternary mixture was introduced into the furnace. THE SATURATOR The saturator unit comprised three glass chambers, as shown in Fig 1, the first two chambers packed with glass beads and partially filed with water and the third empty. Each tower had a glass tube with a stopper attached for the purpose of adjusting the amount of water in it. The unit was immersed in a large oil bath, which was automatically controlled with the help of a thermostat relay to constant temperature, ± 0.05ºC, using thermometers which had been calibrated against a standard platinum resistance thermometer. The performance of the saturator over the range of experimental conditions was checked by weighing the water absorbed from a measured volume of hydrogen; the observed ratio was always within 0.5 pct of theoretical.

Jan 1, 1950

By David H. Browne

(Pittsburg Meeting, March, 1910.) NICKEL has always been a fruitful mother of problems. Previous to the year 1906 nickel was regarded as an element replacing iron in copper-mattes, and it was believed that the same laws which governed the elimination of iron could be applied-to nickel. This conception has lately undergone a complete change, and nickel in all its stages is now regarded as an element replacing copper; in other words, copper-nickel is considered now as two elements, but as one metal. When we commenced our investigations on Monel metal we made a great many experiments on the conversion of mattes, both high copper and high nickel. We studied closely the composition of the mattes and the changes produced by the blow. We found in all cases certain agreements which we believe are due to some law. Briefly stated, our conclusions are as follows 1. Nickel is not an element replacing iron in matte. 2. Nickel-copper alloys act in the matte-blow like one metal. 3. Nickel-copper alloys follow, during the matte-blow, exactly the same laws as govern. the behavior of copper alone. This brings up the question : What are the laws governing the production of metallic copper, and what are the relations copper to sulphur and iron during the Bessemer blow ?

Apr 1, 1910